Heavy Duty Boots are very good, but not broken in my eyes.
The item has quickly become one of the best in the game and for good reason: hazards have always been at the center of our metagames. I understand why it rising to popularity and negating the effect of a fundamental part of our game can be cause for concern, but for every single thing Heavy Duty Boots limits, it also helps open up something entirely new and healthy I feel. On top of this, running Heavy Duty Boots is not a foolproof response to hazards as hazard removal is virtually mandatory on most OU archetypes still and, as the OP mentions, Knock Off is as common as ever.
I understand a lot of people becoming concerned about Heavy Duty Boots ever since Pokemon like Libero Cinderace, which most people believe is broken, or Volcarona, a historically controversial Pokemon, have become prominent and almost always run Heavy Duty Boots. I would even go as far as saying that it is probably that Heavy Duty Boots broke Cinderace. This is a great point for those who believe the item removes a form of counterplay (hazard damage) that is fundamental to our play, but I also want people to consider the positives it brings and the consequences of removing the item universally instead of handling individual Pokemon that may be worthy of tiering attention.
A few examples of how Heavy Duty Boots open up teambuilding in OU are the following:
- Teams can run Heavy Duty Boots on their Slowbro, Dragapult, Zeraora, etc. if they lack a Poison type so they are less susceptible to Toxapex's Toxic Spikes. Toxapex is a great Pokemon right now and accounting for the status and item displacement impacts it has repeatedly with offensive teams is already challenging enough (to the point that we included it in the aforementioned survey), so not forcing teambuilding to be warped around it in yet another fashion is great and opens things up a bit.
- Heavy Duty Boots makes a lot of Pokemon that previously would never have touched OU viable, expanding the metagame and giving us more options both offensively and defensively. People have always complained about how stagnant and standardized OU is, so Pokemon like Rotom-Heat, Togekiss, Incineroar, Mantine, and Talonflame having viability should be welcomed with open arms.
- Heavy Duty Boots leads to a lot of offensive presences being accessible and gets in the way of one of stall's main ways of making progress, through forcing switches with hazards up. I personally do not subscribe a ton to this argument as it goes both ways and I also find stall to be pretty poor in this metagame due to the natural longevity of balance teams invalidating it (see: Magic Guard, Regenerator, etc.), but a lot of people have complained about this in recent generations, so at least there's less room for problems here.
I think that OU can use some work in terms of potential suspects or bans in the future and the council is actively discussing this. The survey we sent out was a great start and I am looking forward to our process continuing into the future; we have made great strides this generation towards being transparent and communicating with the public. A handful of people who responded indicated that they feel Heavy Duty Boots is problematic and I believe ignoring those voices is a poor choice, so this thread felt appropriate.
I hope that people share their opinions throughout this thread, but I do think that we need to consider the potential consequences of a ban of Heavy Duty Boots. It may preserve 1-2 Pokemon in OU (probably just Cinderace), but it will be a departure from our normal approach that requires extreme circumstances to justify and it will also shaft every single lower tier, who (as far as I know) have all not had issues with Heavy Duty Boots (you can argue individual cases like NU Scyther, but I think that a lone case is far from sufficient justification).
Generally, I prefer focusing on suspecting and banning individual Pokemon before focusing on banning non-Pokemon elements (i.e: moves, items, abilities, etc.) unless the element causes various things to be banworthy directly. It is a lot harder to analyze that with Heavy Duty Boots as while it may only bolster Cinderace to "broken status", it has a great impact on how the tier is played, how counterplay is approached in teambuilding, and how games transpire regardless of making individual Pokemon banworthy or not. I understand that because of this we have a very complicated discussion at hand.
The thing is that no matter how we look at this impact that it has, I, much like the OP, do not find it to be broken or uncompetitive. It is a departure from our status quo for sure, but that alone is not enough to raise our pitchforks and demand removal. Entry hazards remain a prominent part of gameplay despite this and their presence in games is nowhere near as fundamental or assumed as a basic mechanic such as switching, which I feel invalidates arguments made about the comparison to Arena Trap/Shadow Tag in the post above.
I think that we should monitor the impact Heavy Duty Boots has on our metagames and a thread like that is perfect for this. However, as it currently stands, a ban seems like a poor idea and we should focus on identifying problematic Pokemon -- be it Pokemon that use Heavy Duty Boots or not -- and working on handling them with our tiering process in the appropriate fashion.